The present invention relates to a cathodoluminescence detection system. It also relates to a microscope implementing such a system.
The field of the invention is the field of cathodoluminescence, and more particularly the field of systems using charged particles such as charged particle microscopes, for example microscopes using the principle of cathodoluminescence.
Numerous cathodoluminescence detection systems coupled with charged particle microscopes are currently known, such as transmission electron microscopes (TEM) and scanning transmission electron microscopes (STEM).
The physical effect used in these microscopes, known as cathodoluminescence, is based on the detection of optical signals emitted due to excitation by a charged particle beam. The microscopes used are equipped with a charged particle cannon producing a charged particle beam that is aimed at a sample under examination. The sample struck by the particle beam is excited and in turn emits light radiation. The light radiation is collected by a collection optic the role of which is to direct the light radiation towards means of analysing said light radiation. So-called adjustment means can be arranged between the collection optic and the analysis means to modify and convey the light radiation to the input of the analysis means. Such a microscope is described in U.S. Pat. No. 7,589,322. The collection optic is located in a vacuum chamber of the microscope.
However, the known cathodoluminescence detection systems are not flexible. These microscopes and the cathodoluminescence detection systems that they implement do not allow for optimised light radiation collection combined with conservation of intensity and radiance (power per unit solid angle per unit area) along the light path to the analysis means. In particular, they do not allow for optimum collection of the optical signal combined with optimum spectral resolution.
An aim of the present invention is to remedy the aforementioned drawbacks.
Another aim of the present invention is to propose a cathodoluminescence detection system that improves the collection of the light radiation.
Moreover, a further aim of the invention is to propose a cathodoluminescence detection system that conserves both the intensity and radiance of the signal collected over the entire light radiation path.